1. Field of the Invention
The present invention relates to a sleeper for supporting rails within a section of track for rail vehicles, the sleeper having longitudinal reinforcing elements which extend along the longitudinal axis of the sleeper.
2. Description of the Background Art
Methods are known for adapting sections of track, i.e., sections of railway track comprising consecutive sleepers to which two parallel steel rails for rail vehicles are attached, to form measuring sections by replacing some of these conventional sleepers with special measuring sleepers and accommodating measuring devices therein, such as force or temperature measuring sensors, in order to use them with a measured value pickup system comprising a measuring device of this type for the purpose of determining physical variables when railbound vehicles pass over them. Such conventional sleepers to be replaced may be various and, in particular, wooden, steel and concrete sleepers, depending on their age, track construction and provided use by rail vehicles.
Methods are furthermore known, for example from DE 103 05 470, for disposing measuring devices of different measured value pickup systems, in particular measuring devices for force measurement, temperature measurement and/or path measurement, on common sleepers. Measuring devices for force absorption are therefore disposed between the rail and the sleeper so that, as a result, measuring devices of different measured value pickup systems may, in principle, be advantageously provided on conventional sleepers or also on conventional rails within a common section of track.
With regard to concrete sleepers for supporting railway rails, a concrete sleeper of this type is known from DE 100 30 998, which has approximately uniformly distributed reinforcing bars in the longitudinal direction of the sleepers which are cast into the concrete bodies under pretension, wherein a connecting plate which is fixedly anchored in the concrete body by reinforcing elements mounted on their undersides and which has fixing elements is provided on the upper face of the sleeper as a pickup element, wherein the connecting plate is mounted in an indentation in the area of the rail bearing in such a way that the surface of the connecting plate lies beneath the upper face of the sleeper, and wherein the fixing elements is designed in such a way that different measuring devices may be mounted thereon beneath the rails for measuring signal detection. A configuration of this type is suitable for force pickup systems, since the sensors used for this purpose are located directly in the rail-to-sleeper flow of force. With regard to temperature pickup systems which are used in the area of bogie monitoring, e.g., for hot box detection or stuck brake detection, the IT sensor used (infrared sensor) is, in part, highly susceptible to errors because of the extreme environmental conditions (weather, dynamic load, dirt). A disposal on the top of the sleeper, for example, is therefore of only limited suitability.
To dispose devices of temperature pickup systems, a special hollow sleeper is therefore ordinarily used as the measuring sleeper. However, these sleepers are substantially more susceptible to vibration, and the entire IT sensor system must therefore be held within the hollow sleeper using vibration dampening elements. The transverse displacement resistance of such special measuring or hollow sleepers is also only moderate with regard to conventional sleepers, in particular compared to concrete sleepers. With regard to such special hollow sleepers as measuring sleepers, reference may be made, for example, to DE 100 60 380 and EP 1 772 342.
A disposal of devices of a temperature pickup system within a hollow track sleeper, which is situated parallel to the conventional sleepers, is furthermore described in DE 42 17 681, which corresponds to U.S. Pat. No. 5,397,900. However, the disposal is such that the hollow track sleeper must be completely removed from the track in order to reach the IR sensor situated within the hollow track sleeper in the event of maintenance or if an error or failure of a temperature pickup system occurs.